Abstract Absorption of NO by liquid absorbents is an important process for pollution abatement. A critical review has been presented for the various reactive solvents recommended for the absorption of NO. A mathematical model has been developed for sizing of packed columns and bubble columns for the absorption of NO. The dimensions of the equipment have been found for 10 reactive solvents and over a wide range of liquid and gas velocities. Several liquid absorbents, namely FeSO 4/H 2SO 4, Fe(II)EDTA, KMnO 4/NaOH, NaClO 2/NaOH, Na 2S/NaOH, Na 2S 2O 4/NaOH, H 2O 2, Na 2SO 3, FeSO 4/Na 2SO 3, and urea have been considered. A procedure has been developed for the selection of the most economic system for the absorption of NO. Economic analysis was done for the various systems based on fixed and variable costs, materials of construction and additional cost for the regeneration of chemicals and recovery of NO gas.